Technical field of the invention The present invention relates to a device for filling and emptying a canister for holding a substance with an opening comprising a body, a filling line, at least a first suction lance and a backflow preventer. Background of the invention

Substances used for cleaning, in particular in industrial washing systems, are often solid substances which usually need to be dissolved and/or diluted by a fluid, for example by water. The dissolved substance is usually stored in a special tank, for example a day tank, in order to be provided, for example, to an industrial washing system. Operating a day tank for holding a dissolved substance increases the operation costs of a washing system and additionally requires additional handling operations by a user.

It is therefore desirable to improve the cost efficiency of a washing system and also to reduce the handling necessary to operate a washing system, in particularly the handling of the washing substance. SUMMERY OF THE INVENTION

This object is solved by means of a device for filling and emptying a canister having the features of claim 1. Preferred embodiments, additional details, features, characteristics and advantages of the object of the invention of said device are disclosed in the sub-claims.

In a general aspect of the invention the device for filling and emptying a canister for holding a substance with an opening comprises a body, wherein the body is connectable to the canister and at least partially insertable into the opening of the canister in a vertical mounted state, a filling line connectable to a fluid supply, wherein the filling line extends at least

partially through the body, and at least a first suction lance extending through the body, wherein the device comprises a backflow preventer, preventing a fluid supplied through the filling line to be sucked back into the filling line.

The canister for holding the substance, in particularly a solid substance, a fluid or a gel-like substance, may be a standard canister comprising at least one opening, for example arranged in a nozzle, wherein the nozzle may be arranged at a top part of the canister. The substance held within the canister may be a substance that is to be diluted and/or dissolved by a fluid, for example by water, in particular by fresh water of drinking quality. The device for filling and emptying the canister

comprises a body, wherein the body may have an

essentially circular shape. The body may consist of one or more parts. The body may at least partially be

inserted into the opening of the canister and may be connected, in particular fluid impermeable, in particular to the nozzle, of the canister. In a mounted state the device may be arranged in an essentially vertical

position within the first opening of the canister. The device comprises a filling line which is connectable to a fluid supply, for example a water mains, wherein the filling line may be permanently connectable to the fluid supply. The filling line may extend at least partially through the body of the device, supplying a fluid from the fluid supply, for example water, into the canister. The fluid may dilute and/or dissolve the, in particular solid, substance inside the canister. In order to extract the diluted and/or dissolved substance from the inside of the canister, the device comprises at least a first suction lance. The at least first suction lance may extend at least partially through the body into the canister, in particular to a bottom part of the canister. The first suction lance may be connectable to a washing machine in order to supply a diluted and/or dissolved substance. The device may comprise multiple suction lances, for example two, three or four suction lances, wherein the suction lances may be connectable to

different washing machines. Further, the device comprises a backflow preventer which may be arranged on or in the filling line. A backflow preventer may be a means or mechanism to prevent the backflow of the fluid towards the fluid supply providing a barrier to the backflow. The basic mechanism for preventing backflow may be a

mechanical backflow preventer, which provides a physical barrier to backflow. A mechanical backflow preventer may comprise a reduced pressure principle assembly, for example the pressure vacuum breaker assembly, and the double check valve assembly. A further type of the mechanical backflow preventer may be a residential dual check valve. The backflow preventer thus prevents the fluid, for example water, supplied through the filling line to get into contact with the fluid supply, for example the water mains, in particular after the supplied fluid has diluted and/or dissolved or gotten into contact with the substance. The back-flow preventer thus may protect the fluid supply from being contaminated by supplied fluid flowing back towards the fluid supply. A backflow in the feeding pipe may occur when, for example, the pressure in the fluid supply becomes a negative pressure, when the fluid is sucked backwards through the filling line towards the fluid supply. Due to the

backflow preventer no diluted and/or dissolved substance may flow back through the filling line towards the fluid supply, for example the fresh water line or water mains, preventing a contamination of the fluid supply. This has the advantage, that the filling line of the device for filling and emptying a canister may be permanently connected to a fluid supply, for example a water mains. This has the advantage that a further tank, for example a day tank, may be omitted when the canister with the substance may be connected directly to the fluid supply. Further, this has the advantage, that unnecessary

handling of the substance may be omitted, thus increasing efficiency and reducing costs.

In another embodiment of the invention the filling line comprises a feeding pipe and a draining pipe, wherein the feeding pipe and the draining pipe are separated and vertically spaced apart, and an overflow, limiting a fluid level inside the body to a maximum fluid level. The filling line comprises a feeding pipe and a draining pipe, both of which are at least partially arranged inside the body of the device for filling and emptying a canister. Inside the body, in particular in a cavity inside the body, the feeding pipe and the draining pipe are separated and vertically spaced apart, in particular by a height h ₂ . The feeding pipe is connectable to a fluid supply, wherein the draining pipe extends at least partially inside the canister, allowing a fluid supplied through the feeding pipe into the body, in particular into the cavity inside the body, in order to drain through the draining pipe into the inside of the

canister. The device further comprises an overflow, wherein the overflow is fluid permeable connected to the cavity inside the body, to the feeding pipe and the draining pipe, connecting the space in between the feeding pipe and the draining pipe, in particular the cavity, to the outside environment. A fluid that is supplied by the fluid supply through the feeding pipe into the body which may not be able to drain through the draining pipe into the canister, may thus flow freely through the overflow of the device to the outside

environment. The overflow is designed and arranged in a way that limits a fluid level inside the body to a maximum fluid level. The maximum fluid level may be spaced apart from the feeding pipe, in particular the lower end of the feeding pipe inside the cavity, by a distance d, thus forming a backflow preventer with an air gap in between the maximum fluid level and the feeding pipe. A flow path of the fluid from the feeding pipe through the body and through the overflow to the outside, may be visible, unobstructed and completely free, forming a free outlet. A free outlet is a constant and vertical flow path between the lowest end of the feeding pipe inside the body, in particular inside the cavity inside the body, and any surface of the supplied fluid, in particular the maximum fluid level inside the body, which is reached in the event of a maximum supply of fluid. Thus the device comprises an air gap which is a vertical, physical separation between the end of the feeding pipe inside the body and a flood-level rim of the body, wherein the flood-level rim roughly corresponds to the lower rim of the overflow, which is arranged in the body of the device. This has the advantage that the fluid supply, for example the water mains, is protected from back suction effects.

In another preferred embodiment of the invention the overflow is a non-circular overflow, arranged in a sidewall of the body. The overflow is of a non-circular shape, wherein the non-circular overflow is arranged in a side wall of the body of the device. The non-circular overflow may limit the fluid level inside the body to a maximum fluid level, wherein the maximum fluid level inside the body may roughly correspond to the flood-level rim of the overflow. The flood-level rim of the overflow may essentially correspond to the lower rim of the overflow, in particularly the rim facing the canister in a mounted state. The flood-level rim may correspond to the surface of a fluid flowing through the overflow over the lower rim. The non-circular overflow may be of an oval or about rectangular cross-sectional shape. The cross-section area of the non-circular overflow may be designed in order to drain the maximum possible supply of fluid through the feeding pipe into the inside of the body under normal pressure conditions in the event of, for example, a malfunctioning of the fluid supply. This has the advantage that the device comprises a backflow preventer in form of a free outlet which allows for a direct connection of the device, in particular the filling line of the device, to a fluid supply, for example a water mains, while protecting the water mains from a backflow of supplied fluid.

In a particularly preferred embodiment of the invention the feeding pipe and the maximum fluid level are spaced apart a distance d, wherein the distance d is at least about 20 mm. The feeding pipe, in particular the end of the feeding pipe inside the body, especially inside the cavity inside the body, and the maximum fluid level are spaced apart a distance d. The distance d may be greater than twice an inner diameter of the feeding pipe. The distance d may be at least about 20 mm, preferably 1 inch. The constant and unobstructed distance between the filling line, in particular the lowest end of the feeding pipe, inside the body and the highest possible fluid level inside the body, for example the maximum fluid level, may be greater than or equal to twice the inner diameter of the feeding pipe, but at least 20 mm. Furthermore, in a preferred embodiment of the invention the device comprises a venting pipe for venting the canister. The device comprises a venting pipe, wherein the venting pipe may extend at least partially through the body, for venting the canister when a fluid is sucked from the canister through a suction pipe, for example towards a washing machine. The venting pipe may be at least partially designed in form of a drill hole and/or a pipe, allowing for example air to be sucked through the overflow, through the venting pipe into the canister. The feeding pipe may be arranged inside the body and may extend above the maximum fluid level.

In a further preferred embodiment of the invention the device comprises a high level switch. The device may comprise a high level switch, wherein the high level switch may be designed in form of a floating switch for controlling the filling level of the fluid inside the canister. The high level switch may move between a low level position and a high level position, and may be electrically connected, for example, to a fluid supply with a pump and/or valve for controlling the amount of fluid supplied to the canister. In the low level

position, for example, the fluid supply may supply a fluid to the inside of the canister until the high level switch reaches the high level position, when the fluid supply may be switched off. This has the advantage that a fluid may automatically be supplied to the canister keeping the fluid level at a defined level.

In a further preferred embodiment of the invention the device comprises a low level alarm. The low level alarm may be designed in form of a floating switch for

detecting a low level of a fluid inside the canister, wherein the low level alarm may be arranged near a bottom part of the canister. The low level alarm may be

electrically connected, for example, to a fluid supply or a controlling circuit. This has the advantage that when the low level alarm is triggered a signal may be given indicating that the fluid, in particular the dissolved or diluted substance inside the canister, has run out and that the canister needs to be replaced with a canister with new substance. In another embodiment of the invention the body comprises a wiring chamber. The wiring chamber may be arranged at a top part of the device, in particular outside of the canister, and may be sealed fluid impermeable. Inside the wiring chamber contacts from the high level switch and/or the low level alarm may be arranged, for example in order to be connected to a plug of a controlling system. This has the advantage that the device, in particularly the high level switch and/or the low level alarm, may be easily and safely connected to a control system.

In another preferred embodiment of the invention the body comprises a fastening element for attaching the body detachable to the canister. The fastening element may be movably ring-shaped designed and positioned around the device, wherein the fastening element may comprise a thread on the inside, which may be designed to match a thread on the outside of for example the nozzle of the canister, in order to screw the fastening element onto the thread on the outside of the nozzle of the canister. This has the advantage that the device may be detachably and safely secured to a canister. In a further embodiment of the invention the device comprises a flow limiting device. The flow limitation device may be arranged inside the device for filling and emptying a canister. The flow limitation device may be connected to the fluid supply and may limit the amount of fluid flowing through the filling line, in particular the feeding pipe, of the device. This has the advantage, that the amount of fluid supplied through the filling line, in particular the feeding pipe, is limited to an amount that is able to flow through the overflow, for example in case of a blockage of the draining pipe. This ensures the reliable functioning of the backflow preventer, in particular the air gap, even when the drainage pipe is blocked .

In a further preferred embodiment of the invention the at least first suction lance is screened against the filling line, in particular against the feeding pipe and the draining pipe. The at least first suction lance may be screened by a hose-in-hose design of the suction lance, for example in form of a double walled suction lance design. The hose-in-hose design may be applied to all suction pipes of the device. The at least first suction lance may be screened by a screening element, which may be designed in form of a partition wall. The screening element may separate, in particular fluid impermeable, a part of the cavity, wherein the at least first suction lance is arrange in the separated part of the cavity, thus, screening the suction lance for example from the rest of the cavity in which the back flow preventer, in particular the air gap, is arranged. This has the

advantage, that condensation water on the outside of the suction lance may be prevented from getting into contact with fluid supplied through the filling line.

A further aspect of the present invention is a system, in particular a suction system, comprising a device for filling and emptying a canister as previously described.

In a further embodiment of the invention the system comprises a flow limitation device. The flow limitation device may be arranged outside the device for filling and emptying a canister and may be connected to the fluid supply and/or the filling line, in particular the feeding pipe, of the device. The flow limitation device may limit the amount of fluid entering the filling line, in

particular the feeding pipe, wherein the fluid may be supplied from a fluid supply like the water mains.

The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pursuant field can be applied without a limitation.

DESCRIPTION OF THE FIGURES

Additional details, features, characteristics and advantages of the object of the invention are disclosed in the sub-claims, the figures and the following description of the respective figures and examples, which - in exemplary fashion - show several embodiments and examples of a device for filling and emptying a canister according to the invention.

In the drawings :

Fig. 1 is a sectional view of a device for filling and emptying a canister in accordance with the invention;

Fig. 2 is a sectional view of a device for filling and emptying a canister connected to a canister;

Fig. 3 is a sectional view of the device for filling and emptying a canister shown in Fig. 1;

Fig. 4 is a schematic side view of the device shown in

Fig. 1 with several suction lances;

Fig. 5 is a schematic side view of the device shown in

Fig. 4 with a non-rectangular overflow.

The device shown in Fig. 1 comprises a body 12 of an essentially circular shape, wherein the body 12 consists of several parts. A filling line 14 which is connectable to a fluid supply (not shown) , comprises a feeding pipe 16 and a draining pipe 18. The feeding pipe 16 and the draining pipe 18 are partially arranged inside the body 12 of the device 10, wherein the feeding pipe 16 and the draining pipe 18 are separated and vertically spaced apart inside a cavity 20 of the body 12. Thus, a fluid may flow through the feeding pipe 16 into the cavity 20 of the body 12, draining from the cavity 20 of the body 12 through the draining pipe 18 into a canister (not shown) . Inside a side wall of the body 12 a non-circular overflow 22 is arranged, connecting the cavity 20 of the body 12 fluid permeable to the outside environment of the device 10. The overflow 22 comprises a lower rim 24 which is limiting a fluid level in the cavity 20 on the inside of the body 12 to a maximum fluid level, by allowing the fluid to freely leave the inside of the body 12 through the overflow 22 to the environment, wherein the maximum fluid level and the lower end of the feeding pipe 16 inside the cavity 20 are constantly vertically spaced apart, forming a backflow preventer 26 in form of a free outlet with a constant air gap. The device 10 further comprises a first suction lance 28, which extends towards a bottom part of a canister (not shown) and partially through the body 12, in order to enable a fluid to be sucked from the canister (not shown) . A venting pipe 30 which is partially designed in form of a drill hole through a part of the body 12 and partially in form of a pipe extending above the maximum fluid level inside the cavity 20 inside of the body 12 is arranged mainly coaxially to the first suction lance 28. At a lower end of the body 12 inside the canister a low level alarm 32 in form of a floating switch is arranged. Further, a high level switch 34 in form of a floating switch is arranged at the body at an upper part. The low level alarm 32 and the high level switch 34 are electrically connected to a wiring chamber 36, wherein the wiring chamber 36 is closed with a lit 38. In order to attach the device 10 removably to a canister (not shown) the device 10 comprises a fastening element 40.

In Fig. 2 the device 10 is shown removably connected to the canister 42 in a mounted state. The canister 42 comprises a nozzle 44 with an opening and an outside thread onto which the fastening element 40 of the device 10 is screwed onto, fastening the device 10 to the canister 42. The body 12 of the device 10 extends towards a bottom part of the canister 42. A fluid, for example water, may be supplied through the feeding pipe 16 into the cavity 20 inside the body 12. The fluid may drain from the cavity 20 of the body 12 through the draining pipe 18 into the inside of the canister 42. Fluid that is not draining into the inside of the canister 42 through the draining pipe 18 may raise the fluid level inside the cavity 20 of the body 12 until the lower rim 24 of the overflow 22 is reached, thus limiting the fluid level to the maximum fluid level. The overflow 22 is a non- circular over-flow, comprising a height hi, wherein hi is for example about 22 mm. The cross-sectional area of the overflow 22 is designed in order to allow the maximum volume of fluid entering into the cavity 20 inside the body 12 through the feeding pipe 16 to freely flow through the overflow 22 to the outside environment, even if the draining pipe 18 is blocked. While keeping a constant distance d between the maximum fluid level and the end of the feeding pipe 16 inside the cavity 20. The distance d may be greater than or equal to twice the inner diameter D of the feeding pipe 16, but at least about 20 mm, preferably 1 inch, wherein d is the distance of the air gap of the free outlet type backflow preventer 26. The distance h.2 between the lower end of the feeding pipe 16 inside the cavity 20 and the spaced apart draining pipe 18 may be greater than the distance d, for example about 37 mm, which is the open distance. The fluid entering the canister 42 through the draining pipe 18 may dissolve and/or dilute a substance (not shown), preferably a solid substance, which may then be drawn out of the canister 42 through the first suction lance 28 for example towards a washing machine. In Fig. 3 a cross-sectional view of the device 10 is shown. The first suction lance 28 is extending partially through the body 12 and through the cavity 20 before being bent about 90° sideways, essentially parallel to the filling line 14. The first suction lance 28 and the filling line 14 are arranged next to each other in order to allow for a faster and improved connectability of the device 10. The filling line 14 comprises the feeding pipe 16 and the vertically spaced apart draining pipe 18, wherein the feeding pipe 16 extends partially inside the cavity 20 of the body 12. In Fig. 4 a perspective side view of the device 10 is shown, wherein the device 10 comprises a second suction lance 46, a third suction lance 48 and a fourth suction lance 50. The suction lances 46, 48, 50 are arranged next to each other and are extending in parallel towards the bottom part of the body 12 which in a mounted state is arranged on the inside near to the bottom part of the canister. The non-circular overflow 26, which comprise an essentially rectangular form, is arranged in the sidewall of the body 12, wherein the suction lances 46,48,50 extend through the cavity 20. At the top part of the device 10 a connection 52 is attached to the body 12 and the wiring chamber, which is closed by a lit 38, in order to allow a cable to the connected to the high level switch 34 and the low level alarm 32 inside the wiring chamber. The arrangements of the first suction lance 28, the filling line 14, the second suction lance 46, the third suction lance 48 and the fourth suction lance 50 next to each other is shown in Fig. 5, allowing a fast and safe connection of the filling line 14 to a fluid supply and of the suction lances 28,46,48,50 to different washing machines. The non-circular, essentially rectangular, design of the overflow 26 is shown in Fig. 6. The suction lances 28,46,48,50 are essentially horizontally arranged together with the filling line 14 adjacent next to each other in a connector plate 54 and are curved by about 90° downwards extending essentially parallel to the body 12 towards the bottom part of the body 12. The suction lances 26,46,48,50 are partially extending through the body 12 and are partially extending essentially in parallel and outside of the body 12 towards the bottom part of the canister.

The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporate by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by the way of example only and is not intending as limiting. In the claims, the wording "comprising" does not exclude other elements or steps, and the identified article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The inventions scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed .

List of reference signs

10 device

12 body

14 filling line

16 feeding pipe

18 draining pipe

20 cavity

22 ove flow

24 lower rim

26 backflow preventer

28 first suction lance

30 venting pipe

32 low level alarm

34 high level switch

36 wiring chamber

38 lid

40 fastening element

42 canister

44 nozzle

46 second suction lance

48 third suction lance

50 fourth suction lance

52 connection

54 connector plate d distance of air gap hi height

h ₂ open distance

D diameter